RESUMO
The main complication of totally implantable venous access devices is deep venous thrombosis on catheter. It may dramatically reduce the already limited venous capacity of patients undergoing chemotherapy and obturate catheters, causing pulmonary embolism or functional disorders. These thromboses usually involve veins of the superior vena cava system where the catheters are implanted. Generally, they occur early, are extensive and often asymptomatic. Doppler ultrasonography is the diagnostic investigation of choice, phlebography being reserved for particular cases or to specify the limits of the thrombus. In a series of 412 vein access devices implanted and systematically monitored by Doppler ultrasonography, we found 57 thromboses (13.8%), 15 partial and 42 complete. The lowest thrombosis rate was observed in the right internal jugular vein (10% vs 20 to 23%, p = 0.006). Thirty-two patients received a systemic fibrinolytic treatment, 16 with streptokinase (SK), five with urokinase (UK), four with tissue plasminogen activator (rt-PA) and seven with SK/UK association. No serious side effects were observed. Sixteen repermeabilizations (50% of fibrinolysis) were obtained. There were no significant differences with respect to the fibrinolytic, the initial characteristics of thrombosis or the patients. Patients without fibrinolysis received 3 weeks of low molecular weight heparin (curative doses) then warfarin. Only one patient was repermeabilized with this treatment (significative difference with fibrinolysis: p = 0.009). Fibrinolysis is indicated in symptomatic thrombosis and/or in cases of extension to the innominate vein or the superior vena cava. Systematic monitoring by Doppler ultrasonography and prophylactic anti-thrombotic treatment are recommended in patients with implantable venous access devices in order to decrease the occurrence of thromboses, to detect asymptomatic patients at an early stage and to increase the effectiveness of fibrinolysis.